This project will establish for the first time, the archaeological diversity of assembly and administration in north-western European societies after the collapse of the Roman Empire (AD 400-1500). We will examine how these sites formed and changed and how differing social modes of organisation impacted and interacted with each other and therefore engage with one of the largest European and global current research themes: how complex societal organisation develops and what social mechanisms facilitate the transition from localised organisations and micro-polities to large-scale kingdoms and nation states. Through a strict methodological framework, expressed as four themes, the key question will be approached in the same manner in Scandinavia and the areas of comparison. GIS will serve as the main analytical tool together with visual analysis, GPS-survey and archaeological fieldwork. Asking questions from archaeological and written sources, the CRP will address the following: did assemblies become more uniform over time, how were assemblies located within the administrative landscape, and who controlled the assemblies? Which social groups and genders could access meetings, and how have these sites contributed to modern collective identities? Despite the significance of assemblies for state formation, their locations and the processes that took place there remain underexplored. The proposed cross-national approach has not previously been attempted and will provide a whole new view of the assembly institution.